Mechanical movement



IF. H. RICHARDS. MECHANICAL MGVEMENT.

No. 403 217. A Patented May 14, 1889..

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@wimm Smmro@ NITED STATES PATENT OFFICE.

FRANCIS H. RICHARDS, OF SPRINGFIELD, MASSACHUSETTS, ASSIGNOR TO lDAR-IEN W. DCDSON, OF VVILKES-BARRE, PENNSYLVANIA.

MEoHANlcAL MOVEMENT.

SPECIFICATION forming part of Letters Patent No. 403,217, dated May 14,1889. Application filed December 18, 1886. Renewed May Z, 1888. SerialNo. 272,538. (No model.)

.To all whom may concern.'

Be it known that I, FRANoIs H. RICHARDS, a citizen of the United States,residing at Springfield, in the county of Hampden and State ofMassachusetts, have invented certain new and useful Improvements inMechanical Movements, of which the following is a specification.

This invention relates to that class of mechanical movements whichincludes the one described and claimed in my application, Serial No.218,973; and the present invention consists in certain improvements inthe latch mechanism which forms a part of the subject-matter of my saidprior application, as hereinafter more fully set forth.

In the drawings accompanying and forming a part of this specification,Figure 1 is a plan view of so much of a mechanical Inovement of theclass specied as embodies my present invention. Fig. 2 is a sectionalside elevation of the latch and key mechanism of the same, showing thelatch set ready for use. Figs. 3, 4, and 5 are similar viewsillustrating the mode of operation of the parts shown in Fig. 2.

Similar characters designate like parts in all the figures.

The frame work A, ofany preferred construction adapted to carry themechanism, has a stud or shaft,D, on which turns a revoluble frame orturret, II, that carries the shaft 6, having thereon the starting-arm26. Said frame also has formed therein a suitable bearing for areciprocating latch, 50, which is thrown forward (toward the left hand,as

hshown in the drawings) by a spring, 52, acting through rod 53 againstprojection 54 formed on said latch, a suitable stop, as 55, beingprovided to properly limit the forward movement of the latch. Theobject, construction, and mode of operation of these-several parts arefull described in my aforesaid application, Serial No. 218,973, to whichreference may be had.

According to my present invention, the latch 50 has pivoted thereto, at3, a latchpawl, 4, arranged to engage with a notch or corner, as 5. onframe A. Said pawl may be so constructed as to operate by gravity; but

I prefer to use some sort of spring, as 2, to normally hold the pawl inthe position shown in Figs. 2, 4, and 5. For operating it to unhook thelatch, said pawl has a projecting arm or lever, 7, adapted to be struckby a similar part of a latch-tripping device. This device comprises acarrier having a movement (usually a sliding one, as shown) crosswise tothe movement of latch 50, a key and return-spring operating saidcarrier, a snap pawl or catch on the carrier and operating thelatch-pawl, and preferably a detent resisting the first movement of saidcarrier.

In their preferred form those several parts are constructed and arrangedas follows: The carrier consists of a vertical spindle or slide, 10,whose lower end, l1, iits freely in a bearing in frame A, and whoseupper end, 13, fits, freely within the verticallysliding key l2, whichkey has its bearing in frame A. Said spindle is supposed to be kept fromrotating by a key or spline, or other means. (Not shown.) It has a pin,14, working in slot lof'key 12, (or some device equivalent to these, butnot shown,) for regulating the relativefstrokes of itself and said key,is constructed to carry the snap-pawl, and has a detent-arm, 16, formedthereon. Said arm normally rests on the beveled or inclined detent-notch17 of the detent-spring 18, as in Figs. 2 and 5; but on the firstdownward movement of the carrier the detent-spring is forced back, as inFigs. 3 and 4, and no longer materially resists the further downwardmovement of said carrier.

The snap-pawl consists of an arm or lever, as 20, pivoted to (or in) thecarrier at 21, and limited ,in its upward movement by stop 19. This pawlis or may be normally held in place (with its point directly over arm 7)yby pullspring 22, connected to arm 23 of the pawl and to the carrier at24. A push-spring, 25, serves to uplift the carrier and key, and anothersimilar spring, 28, intermediate to said carrier and key, transmitsmotion from the key 12 to the carrier.

The operation of this apparatus is as follows: The latch being hookedback, and the other parts standing as in Fig. 2, the operator pressesdown key 12, as in Fig. 3, or until .by the compression of spring 28sufficient force IOO is exerted on slide 10 to drive back detent 18, andthus allow said spring 2G to instantly complete the downward movement ofsaid slide, as also shown in 3. This downward movement is suflicient tocarry pawl 20 against and past arm 7 of pawl 4, thereby unhooking saidpawl and permitting the latch to be thrown forward, (toward the lefthand,) as in Fig. Suppose, now, that the arm 2G immediately returnslatch 50, and that this is hooked back, as in Fig. 4f, the carrier beingstill down, as there shown. The arm 2O will then stand beneath arm 7,and will on the upward return movement of the carrier turn on its pivot21 and thereby escape interference, as illustrated in Fig. 5. If thecarrier could always be allowed to return before the return of thelatch, it is evident the arm 2O could then be integral with saidcarrier; but in practice this is rarely possible, and never to be reliedon, since the latch moves very quickly, so that its outward and returnstrokes together occupy only a very small fraction of asecoiidwsoinetimes less than the fiftieth part thereof.

To the extreme rapidity of movement of the latch is due the utility ofthe detent device in the combinations shown, for unless the downwardmovement of arm 2O is itself very sudden this arm may not pass down farenough and rapidly enough to escape the arm 7 of the returninglatch-pawl 4c; but the detent device insures that the movement when oncebegun shall be instantly completed.

It will be understood that this latch mechanism is capable ofmodification in various ways and degrees, after the manner of machinesin general, within the scope and limits of my invention.

This latch mechanism is applicable as a 4o wheel-starting apparatus totypewriters of the general class which includes the typewriter describedin United States Patent No. 299,751, granted to D. W'. Dodson, June 3,1884-that is to say, to type-writers whose types or type-wheels haveindependent orbital and axial rotary movements.

Having thus described my invention, I claimi 1. The combination, in alatch mechanism of the class described, of the latch carryinga pawl thatterminates in an arm wherebyit is operated, a carrier having a movementcrosswise to the latch-movement, and an arm projecting from saidcarrier, to strike and unhook said pawl, said carrier being operatedfrom a key, all substantially as set forth.

2. The combination of the latch and its pawl, a carrier having` asnap-pawl, 20, a detent resisting` the first movement of said carrier,and a key and springs operating in connection with the detent to :imparta sudden movement to said carrier, all substantially as set forth.

3. The combination of a reciprocating carrier having a detent-arm, aspring having a corresponding detent-notch, a key, and a springintermediate to said key and carrier, all operating substantially as andfor the purpose set forth.

4. The combination of carrier 10, having arm 1G, spring' 18, havingnotch 17, spring 25, key 12, and spring 2S, all constructed andoperating substantially as shown and described.

FRANCIS H. RICHARDS.

lVitnesses:

WIL'BUR M. STONE, DAMEN W. DoDsoN.

